File:Parabolic antenna types2.svg

This is a file from the Wikimedia Commons
From English Wikipedia @ Freddythechick

Original file ‎(SVG file, nominally 850 × 1,820 pixels, file size: 23 KB)

Any autoconfirmed user can overwrite this file from the same source. Please ensure that overwrites comply with the guideline.

Summary

Description
English: Diagram showing the most common types of parabolic antenna feeds.
The reflecting surfaces are shown in red, the feed antenna in green, and typical supporting structures in blue. A few typical rays are shown, in black. The types are:
  1. Axial or front feed This is the most common type, with the feed antenna suspended in front of the dish on the beam axis, at the focal point, pointed back toward the dish. One drawback of this type is that the feed and its supports partially block the beam.
  2. Off-axis feed or offset-feed The primary reflector is asymmetric, with the focus, and the feed, located to one side, outside the beam area. This avoids the problem of the feed obstructing the beam. It is used in home satellite dishes.
  3. Cassegrain In this design, the feed is located on or behind the dish, and its beam illuminates a small hyperboloidal secondary reflector at the focus of the dish, which reflects the beam back to the parabolic dish. It is used in antennas with bulky or complicated feeds, such as satellite ground antennas and radio telescopes.
  4. Gregorian This is similar to the Cassegrain, except the secondary reflector has a concave ellipsoidal shape.
Date
Source Own work
Author Chetvorno
Permission
(Reusing this file)		 I, Chris Burks (Chetvorno), the author of this work, release it into the public domain for any use whatever.
Other versions

Derivative works of this file:

SVG development
InfoField
 
The SVG code is valid.
 
This diagram was created with Inkscape.
 
 This diagram uses embedded text that can be easily translated using a text editor.

Licensing

Public domain I, the copyright holder of this work, release this work into the public domain. This applies worldwide.
In some countries this may not be legally possible; if so:
I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

Captions

A diagram showing the most common types of parabolic antenna feeds.

Items portrayed in this file

depicts

inception

25 November 2010

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current06:43, 13 July 2011Thumbnail for version as of 06:43, 13 July 2011850 × 1,820 (23 KB)wikimediacommons>ChetvornoAdded to label for "axial feed" antenna a more common name for this type of feed: "front feed"
Retrieved from "https://enwiki.freddythechick.net/wiki/File:Parabolic_antenna_types2.svg"